1. Field of the Invention
This invention relates to a single-reel type tape cartridge for magnetic recording-reproducing apparatus.
2. Prior Art
Tape cartridges of the type using a single reel have already been proposed, e.g., in Japanese Patent Application Kokai No. 58-169380. FIG. 3 is a plan view of a single-reel type cartridge 100 disclosed in the specification of the above-mentioned application. A housing 102 is shown containing a length of magnetic tape 106 wound round a single reel consisting of a turnable hub 104 and a flange 108. Housing 102 has an opening 160 formed at one corner, where a block-receiving recess 118 is provided and a leader block 116 for tape insertion is removably fitted in the recess. Leader block 116 has a groove 150 in which the beginning of magnetic tape 106 is secured in position with an engaging pin 152. On the outer side of leader block 116 is formed another groove 154 to receive securely a draw-out pin which comes out of a recording-reproducing apparatus (hereinafter referred to as a xe2x80x9crecorderxe2x80x9d) and draws out leader block 116 from the housing.
When cartridge 100 is used, an automatic loader of the recorder operates to drive the draw-out pin (not shown) first into groove 154 and into engagement with leader block 116. The pin then draws leader block 116 out, puts it in a position along a given tape path of the recorder, and eventually accommodates leader block 116 fixedly in a recess provided along the periphery of the hub of a take-up reel of the recorder. When the tape is to be rewound, leader block 116 is brought back to the position shown in the opening of cartridge 100 by way of a route reverse to that described above.
In the tape cartridge of the type described in the Patent Application Kokai No. 58-169380, the leader end of the tape is fixed to leader block 116 with the aid of pin 152 of soft synthetic resin. Since it is desirable that pin 152 be made of a material easy to fit in the groove of the leader block and which is capable of tightly retaining the tape, the material in common use has been an elastomer.
In the conventional tape cartridge, as described above, the beginning of the tape is fixed to leader block 116. The leader block is designed to enter a recorder to constitute a part of the periphery of a reel onto which the tape is to be taken up. For that reason the block has to be machined with such high precision that providing every cartridge with the block is not economically justifiable. To avoid the cost disadvantage, it might be considered possible as an alternative to affix the beginning of the tape to a pin-like leader, while the function of a leader block is transferred to the recorder, so that the cartridge can utilize only the leader for the purpose of drawing the tape out. For such an arrangement, however, the synthetic resin pin referred to above cannot be used because of its inadequate mechanical strength.
If the pin-like leader is composed of a pin member round which the beginning of the tape is wound securely and a C clamp of an elastomer which is fitted around the pin member, the clamp is still too soft to provide the firm grip required. For positive fixing, it would further be necessary to fit a metal clamp (C-shaped with partial notches) around the C-clamp.
However, an elastomer C-clamp is soft and little slippery, and causes difficulty in fitting a metal clamp around it.
In addition, elastomer clamps absorb the vibration inside a parts feeder and do not lend themselves to automatic assembling.
The present invention provides a tape cartridge comprising a housing, a single tape reel around which a length of tape is wound and which is turnably held within the housing, a leader to which the beginning of the tape is secured, and a tape draw-out member by which the tape is pulled out through an opening formed in the housing into a recorder, characterized in that the leader is composed of a pin member, an elastomer clamp member which is fitted around the pin member, a metal clamp member fitted around the elastomer clamp member, and a highly slippery member of synthetic resin placed between the elastomer and metal clamp members.
A highly slippery member of synthetic resin put between an elastomer clamp member and a metal clamp member improves the sliding contact between the latter two members and facilitates the fixing of a tape to a leader.
Moreover, fitting a highly slippery synthetic resin member over an elastomer clamp member and combining them integrally in advance renders it possible to use a parts feeder, make the tape clamping easy, and improve the efficiency of assembling single-reel type tape cartridges.